U.S. patent application number 11/103953 was filed with the patent office on 2005-08-18 for chemical array fabrication and use.
Invention is credited to Cattell, Herbert F..
Application Number | 20050181436 11/103953 |
Document ID | / |
Family ID | 25104242 |
Filed Date | 2005-08-18 |
United States Patent
Application |
20050181436 |
Kind Code |
A1 |
Cattell, Herbert F. |
August 18, 2005 |
Chemical array fabrication and use
Abstract
A method of using an addressable array of biopolymers on a
substrate includes receiving the addressable array and an
associated machine readable identifier carried on an array
substrate or array housing. The array is exposed to a sample and
read, and the identifier machine read as an identifier signal.
Biological function data for one or more of the biopolymers is
retrieved from a memory based on the identifier signal. Other
methods in which first and updated sets of feature characteristic
data may readily be provided to array users, and methods of
generating arrays are also provided, as are apparatus and computer
program products which can execute a method for generating or using
arrays.
Inventors: |
Cattell, Herbert F.;
(Mountain View, CA) |
Correspondence
Address: |
AGILENT TECHNOLOGIES, INC.
Legal Department, DL429
Intellectual Property Administration
P.O. Box 7599
Loveland
CO
80537-0599
US
|
Family ID: |
25104242 |
Appl. No.: |
11/103953 |
Filed: |
April 11, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11103953 |
Apr 11, 2005 |
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09775387 |
Jan 31, 2001 |
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6879915 |
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Current U.S.
Class: |
435/6.11 ;
702/20 |
Current CPC
Class: |
B01J 2219/00565
20130101; B01J 2219/0054 20130101; G16B 25/30 20190201; B01J
2219/00605 20130101; B01J 2219/00702 20130101; B01J 2219/00527
20130101; B01J 2219/00637 20130101; B01J 2219/00689 20130101; B01J
19/0046 20130101; B01J 2219/0061 20130101; B01J 2219/00612
20130101; B01J 2219/00529 20130101; B01J 2219/00585 20130101; C40B
70/00 20130101; B01J 2219/00641 20130101; G16B 50/00 20190201; G16B
25/00 20190201; B01J 2219/00596 20130101; B01J 2219/00695 20130101;
B01J 2219/00659 20130101 |
Class at
Publication: |
435/006 ;
702/020 |
International
Class: |
C12Q 001/68; G06F
019/00; G01N 033/48; G01N 033/50 |
Claims
1-36. (canceled)
37. A method of using an addressable array of biopolymers on a
substrate, comprising: (a) receiving an array of addressable
biopolymer regions and an associated machine readable identifier
carried on an array substrate or array housing; (b) machine reading
the identifier as an identifier signal; and (c) retrieving updated
biological function data for one or more of the biopolymers from a
memory based on the identifier signal, wherein the retrieved
biological function data comprises information on the function of a
target of the array, or its complement, or the gene from which
either originated; wherein the retrieval of the biological function
data includes: communicating the identifier signal to a processor
which retrieves data on the identity and biological function of the
biopolymers based on the read identifier.
38. The method of claim 37, wherein the biopolymers are
polynucleotides.
39. The method of claim 38, wherein the biopolymers are DNA.
40. The method of claim 37, wherein the memory from which
biological function data is retrieved is a portable storage medium
received from a remote location.
41. The method of claim 37, wherein the processor which retrieves
the biological function data and the memory from which the
biological function data is retrieved, are remote from the location
at which the array and identifier are read, and wherein the read
identifier or identity data is communicated to the remote
processor.
42. The method of claim 37, wherein the method further comprises
exposing the array to a sample, and reading the array.
43. The method of claim 42, wherein the machine readable identifier
is read while the array is in a same apparatus which reads the
array.
44. The method of claim 42, further comprising obtaining a
communication address which is used to establish communication with
the remote processor.
45. The method of claim 42, further comprising retrieving
biopolymer identity data from a memory carrying multiple
identifiers in association with the biopolymer identity data, using
the identifier signal, and wherein the biopolymer identity data is
communicated to the remote processor to retrieve the biological
function data in response.
46. The method of claim 37, wherein the retrieved biological
function data comprises information on the gene from which a target
or its complement originated.
47. The method of claim 37, further comprising retrieving feature
characteristic data for one or more features on the array based on
the identifier signal.
48. The method of claim 47, wherein the feature characteristic data
includes an indication of a suspected feature error.
49. The method of claim 47, wherein the suspected feature error is
selected from the group consisting of: an error in dimension, an
error in location, presence or absence of the feature at a
location, and amount of biopolymer present at the feature.
50. The method of claim 37, further comprising controlling
processing information obtained from the array in accordance with
the retrieved biological function data.
51. The method of claim 42, further comprising controlling reading
of the array in accordance with the retrieved biological function
data.
52. A method of using an addressable array of biopolymers on a
substrate, comprising: (a) receiving an array of addressable
biopolymer regions and an associated machine readable identifier
carried on an array substrate or array housing; (b) machine reading
the identifier as an identifier signal; and (c) retrieving updated
feature characteristic data for one or more of the biopolymers from
a memory based on the identifier signal, wherein the retrieval of
the feature characteristic data includes: communicating the
identifier signal to a processor which retrieves data on feature
characteristics based on the read identifier.
53. The method of claim 52, wherein the feature characteristic data
includes an indication of a suspected feature error.
54. The method of claim 53, wherein the suspected feature error is
selected from the group consisting of: an error in dimension, an
error in location, presence or absence of the feature at a
location, and amount of biopolymer present at the feature.
55. The method of claim 52, wherein the method further comprises
saving into a memory, a first set of feature characteristic data
for an array, retrieving an updated set of feature characteristic
data based on the identifier signal, wherein feature characteristic
data from the first set for a given feature is replaced with
corresponding data from the updated set when the first set data
conflicts with the updated set data.
56. The method of claim 52 additionally comprising communicating
feature characteristic data for an array to a remote location in
association with an identification of the feature.
57. The method of claim 56 wherein the communicated feature
identification includes the array identifier.
58. A method of claim 57 wherein the received updated set of
feature characteristic data is communicated from a remote location
in response to receipt of the read array identifier.
59. The method of claim 57 wherein the updated set of feature
characteristic data is received on a portable storage medium.
60. A method of generating addressable arrays of biopolymers on a
substrate, comprising: (a) providing biopolymers for an array on
different regions of the substrate so as to fabricate the array;
(b) applying an identifier to the substrate of the array or a
housing carrying the substrate; (c) saving in a memory, data on the
identity of the biopolymers on the array associated with the
identifier; (d) providing the fabricated array to a location remote
from the fabrication location; (e) forwarding to the remote
location, updated feature characteristic data or updated biological
function data associated with at least one array identifier,
wherein the biological function data comprises information on the
function of a target of the array, or its complement, or the gene
from which either originated; and (f) communicating to a remote
location an updated set of data for an array in response to a
received communication of the identifier corresponding to that
array.
61. An array fabrication station, comprising: (a) an array
fabricator to provide biopolymers onto different regions of a
substrate so as to fabricate an array; (b) a writing system which
applies a map identifier to a substrate or a housing carrying the
substrate; (c) a processor which saves in a memory, data on the
identity of the biopolymers for each array, in association with the
identifier for that array; and which saves in a memory first sets
of feature characteristic data or biological function data for the
array in association with the array identifier; and which saves in
a memory an updated set of feature characteristic data and/or
biological function data for at least some of the features of the
array, in association with the array identifier.
62. The array fabrication station of claim 61, wherein the
processor retrieves feature characteristic data and/or biological
function data at predetermined time intervals from one or more
remote stations.
63. The array fabrication station of claim 62, wherein the
processor communicates updated data to one or more remote locations
in response to receipt of a communicated identifier for the
array.
64. The array fabrication station of claim 61, wherein in response
to received read data from the array associated with the
identifier, the processor updates feature characteristic data
and/or biological function data.
Description
[0001] This application claims priority to copending application
Ser. No. 09/775,387, filed Jan. 31, 2001, under 35 U.S.C. 120, the
entirety of which is incorporated herein by reference.
FIELD OF THE INVENTION
[0002] This invention relates to arrays, particularly biopolymer
arrays (such polynucleotide arrays, and particularly DNA arrays)
which are useful in diagnostic, screening, gene expression
analysis, and other applications.
BACKGROUND OF THE INVENTION
[0003] Arrays of biopolymers, such as arrays of peptides or
polynucleotides (such as DNA or RNA), are known and are used, for
example, as diagnostic or screening tools. Such arrays include
regions (sometimes referenced as features or spots) of usually
different sequence biopolymers arranged in a predetermined
configuration on a substrate. The arrays, when exposed to a sample,
will exhibit a pattern of binding which is indicative of the
presence and/or concentration of one or more components of the
sample, such as an antigen in the case of a peptide array or a
polynucleotide of particular sequence in the case of a
polynucleotide array. The binding pattern can be detected by
reading the array, for example, by observing a fluorescence pattern
on the array following exposure to a fluid sample in which all
potential targets (for example, DNA) in the sample have been
labeled with a suitable fluorescent label.
[0004] Methods of fabricating biopolymer arrays can be fabricated
using light directed methods, in situ synthesis methods or
deposition of the previously obtained biopolymers. In known light
directed synthesis methods the aim is to form an array of
oligonucleotides on a surface by removing a photoremovable group
from a surface, coupling a monomer to the exposed region of the
surface, and repeating the process. The in situ synthesis methods
include those described in U.S. Pat. No. 5,449,754 for synthesizing
peptide arrays, as well as WO 98/41531 and the references cited
therein for synthesizing polynucleotides (specifically, DNA). Such
in situ synthesis methods can be basically regarded as iterating
the sequence of depositing droplets of: (a) a protected monomer
onto predetermined locations on a substrate to link with either a
suitably activated substrate surface (or with a previously
deposited deprotected monomer); (b) deprotecting the deposited
monomer so that it can now react with a subsequently deposited
protected monomer; and (c) depositing another protected monomer for
linking. Different monomers may be deposited at different regions
on the substrate during any one iteration so that the different
regions of the completed array will have different desired
biopolymer sequences. One or more intermediate further steps may be
required in each iteration, such as oxidation and washing
steps.
[0005] The "deposition method" basically involve depositing
previously obtained biopolymers at predetermined locations on a
substrate which are suitably activated such that the biopolymers
can link thereto. The deposited biopolymers may, for example, be
obtained from synthetic or biological sources. Biopolymers of
different sequence may be deposited at different regions of the
substrate to yield the completed array. Washing or other additional
steps may also be used. Typical procedures known in the art for
deposition of polynucleotides, particularly DNA such as whole
oligomers or cDNA, are to load a small volume of DNA in solution in
one or more drop dispensers such as the tip of a pin or in an open
capillary and, touch the pin or capillary to the surface of the
substrate. Such a procedure is described in U.S. Pat. No.
5,807,522. When the fluid touches the surface, some of the fluid is
transferred. The pin or capillary must be washed prior to picking
up the next type of DNA for spotting onto the array. This process
is repeated for many different sequences and, eventually, the
desired array is formed. Alternatively, the DNA can be loaded into
a drop dispenser in the form of an inkjet head and fired onto the
substrate. Such a technique has been described, for example, in PCT
publications WO 95/25116 and WO 98/41531, and elsewhere. This
method has the advantage of non-contact deposition. Still other
methods include pipetting and positive displacement pumps such as
the Biodot equipment (available from Bio-Dot Inc., Irvine CA,
USA).
[0006] In array fabrication, the quantities of DNA available for
the array are usually very small and expensive. Sample quantities
available for testing are usually also very small and it is
therefore desirable to simultaneously test the same sample against
a large number of different probes on an array. These conditions
require use of arrays with large numbers of very small, closely
spaced spots (features). Due to the precision required, and to
maintain costs low, it will often be desirable to have the arrays
fabricated at a fabrication facility and then shipped to the end
user. The present invention realizes that during the fabrication
process small errors may result which do not make a given array
useless provided they are communicated to an end user of the array
so he can interpret the data obtained from reading an array exposed
to a sample accordingly. Such small errors may include, for
example, incorrect feature size, complete absence of one feature,
or slightly incorrect feature location. However, the present
invention further realizes that at any later time following array
fabrication one or more previously detected errors in any of the
thousands of features on a typical array, may be found. It would be
desirable if the nature of such later detected errors could quickly
and conveniently be provided to many end users of the different
arrays from a central fabrication facility. Furthermore, it would
be desirable if later discovered biological function data
associated with one or more features of an array could similarly be
provided to many end users. The present invention further realizes
that when many arrays with the same set of features are provided to
many different end users, there is the opportunity for them to
discover feature errors or biological function data associated with
features which could be advantageously shared with others. It would
be desirable then, to provide a means by which array users could
quickly and easily obtain the benefit of prior users' discoveries
of any quality issues or biological function data associated with
array features.
SUMMARY OF THE INVENTION
[0007] The present invention then, provides in one aspect a method
of using an addressable array of biopolymers (such as
polynucleotides, particularly DNA, or peptides) on a substrate. The
method includes receiving the addressable array and an associated
machine readable identifier carried on an array substrate or array
housing. The array may be exposed to a sample and read.
Additionally, at any point in this method the identifier may be
machine read as an identifier signal. The machine readable
identifier may be read while the array is in a same apparatus which
reads the array, but this is not required. Biological function data
may be retrieved for one or more of the biopolymers from a memory
based on the identifier signal. One method for the retrieval of the
biological function data includes communicating the identifier
signal to a processor which retrieves data on the identity of the
biopolymers based on the read identifier. Such biopolymer identity
data can be any type of data which distinguishes different
biopolymers on the array (for example, biopolymer sequences or
molecular weights of different biopolymer fractions obtained from a
particular restriction fragment experiment on a particular
polynucleotide sample, or that a biopolymer was received from a
particular source). The identity data on the biopolymers is
communicated to a processor which retrieves the biological function
data for one or more of the biopolymers from a memory based on the
retrieved identity data. Optionally, the processor which retrieves
the biological function data and the memory from which the
biological function data is retrieved, may be at a location (such
as a central fabrication station) remote from the location at which
the array and identifier are read (such as at an end user station).
In such case, the read identifier or biopolymer identity data is
communicated to the remote location and the biological function
data is received in response. Another method for retrieval is from
a memory which is a portable storage medium (such as may be
received from a remote location).
[0008] In the situation where communication with a remote location
is used, the method may also include obtaining a communication
address of the remote station using the identifier signal. For
example, the communication address may be included as part of the
identifier or it may be retrieved from a database of communication
addresses associated with at least part of respective identifiers.
In one example, the database lists the communication address of a
particular fabricator which fabricated all arrays with a
predetermined portion of an identifier. The communication address
so obtained may be used to establish communication with the remote
station.
[0009] The present invention further provides a method of using an
addressable arrays of biopolymers on a substrate which may, for
example, be executed at a location sometimes referenced as an end
user station. In one aspect, the method includes receiving the
addressable arrays with respective associated machine readable
identifiers carried on an array substrate or array housing. Each
array is exposed to a sample and read. At any stage, the array
identifier is machine read as an identifier signal. A first set of
feature characteristic data for each array received from a remote
location is saved into a memory. An updated set of feature
characteristic data for at least some of the features of at least
some of the arrays, received from a remote location, is also saved
into a memory (which may be the same or different from the memory
into which the first set is saved). Either or both of the first and
updated sets may be received by communication from a remote
location (such as a central fabrication station) in response to
receipt at the remote location of a communication of the read array
identifier, or received on a portable storage medium. The saved
first and updated sets of feature characteristic data for each
array is retrieved using the read identifier signal. One way of
accomplishing this includes replacing feature characteristic data
from the first set for a given feature with corresponding data from
the update set when the first set data conflicts with the updated
set data.
[0010] The method of using may additionally include communicating
feature characteristic data for an array to a remote location in
association with an identification of the feature (such
identification including, for example, the array identifier and
feature location within the array, or an identification of the
biopolymer at the feature for which characteristic data is
communicated). Feature characteristics includes any one or more of
feature physical characteristics, for example, an indication of a
suspected feature error, and biological function data for one or
more of the biopolymers. Examples of suspected feature errors
include errors in dimensions (such as total area), location,
presence (for example, an expected feature is missing), or amount
of biopolymer present at a feature. The method of using may also
include communicating feature characteristic data that is not
directly used for feature extraction, such as biological function
data for one or more features (for example, feature sequence) if
previously unknown.
[0011] The present invention further provides a method of
generating addressable arrays of biopolymers on a substrate. Such a
method includes providing the biopolymers for each array on
different regions of the substrate so as to fabricate the array
with features of different composition. An identifier is applied to
the substrate of each array or a housing carrying the substrate,
different identifiers being applied for arrays having different
sets of features. Data on the identity of the biopolymers on each
array in association with the corresponding identifier may
optionally be saved into memory. The fabricated arrays and a first
set of feature characteristic data associated with at least one
array identifier, may be forwarded to multiple different remote
locations (such as locations of end users of the array). An updated
set of feature characteristic data for an array is also
communicated to one or more remote locations (such as a location of
an end user of the array) in response to a received communication
of the identifier corresponding to that array from a remote
location. Alternatively, the updated set of feature characteristics
may be forwarded by shipping a portable storage medium carrying the
data to the one or more remote locations (such as those locations
to which corresponding arrays were shipped) Alternatively or
additionally to forwarding first and updated sets, biological
function data for one or more of the biopolymers on an array may be
forwarded to a remote location (such as by communication in
response to a received communication of the identifier for that
array).
[0012] In one aspect, the method of generating arrays may
optionally further include receiving feature characteristic data
for an array in association with an identification of the feature,
communicated from a remote location (such as an end user). The
received feature characteristic data may be for a sub-set of
features on a first array and may be received in association with
an array identifier corresponding to the first array. The updated
set of feature characteristic data communicated to a remote
location as previously described, may optionally include the
received feature characteristic data for the sub-set of features.
In this manner, this aspect of the invention allows, for example,
end users to provide feature characteristic data which can be made
available from a fabrication station as update data for other
remote locations (for example, other end users such as upon receipt
from such other end users of a communicated identifier for a first
array).
[0013] The present invention further provides apparatus which can
execute one or more methods of the present invention. In one
aspect, for example, an apparatus for using an addressable array of
biopolymers on a substrate has an array reader which reads the
array following exposure to a sample. A reader (which may be the
same or different from the array reader) reads an identifier
carried on an array substrate or an array housing, as an identifier
signal. A processor is also provided to perform any or all of the
steps of a method of the invention, which can be performed by a
processor. For example, the processor may retrieve biological
function data for one or more of the biopolymers from a memory
(such as a portable storage medium in a portable storage medium
reader) based on the read identifier signal (such as by retrieving
data on the identity of the biopolymers based on the read
identifier; and retrieving the biological function data for one or
more of the biopolymers from a memory based on the retrieved
identity data). As another example, the processor may either
control reading of the array or process information obtained from
reading the array, in accordance with the retrieved biological
function data. The apparatus may further include a communication
module through which the processor may perform any communication
functions required by the method. As a further example, the
processor may retrieve feature characteristic data for the array
from a memory based on the read identifier signal, communicate
feature characteristic data for the array to a remote location in
association with an identification of the feature, and/or
additionally obtain a communication address for the remote location
using the identifier signal as described above.
[0014] In still another aspect of the apparatus, a central
fabrication station is provided which includes an array fabricator
to provide biopolymers onto different regions of multiple
substrates so as to fabricate arrays. A writing system is also
included which applies a map identifier to each substrate or a
housing carrying the substrate, different identifiers being applied
for arrays having different sets of features. The processor in this
aspect save into a memory: data on the identity of the biopolymers
for each array, in association with the identifier for that array;
first sets of feature characteristic data for the arrays each in
association with the array identifier; and an updated set of
feature characteristic data for at least some of the features of at
least some of the arrays, each in association with a corresponding
array identifier, which saving occurs at a time later than the
saving of the first sets of feature characteristics. One same
memory or different memories may be used for saving the foregoing
items.
[0015] The present invention further provides a computer program
product, comprising: a computer readable storage medium having a
computer program stored thereon for performing, when loaded into a
computer communicating with a suitable apparatus (such as at a
fabrication or end user station) will cause execution of any one or
more methods of the present invention.
[0016] One or more of the various aspects of the present invention
may provide one or more of the following, or other, useful
benefits. For example, errors detected after array fabrication may
quickly and conveniently be provided to many end users of the
different arrays from a central fabrication facility. Furthermore,
later discovered biological function data associated with one or
more features of an array may be provided to many end users.
Additionally, there is the opportunity for some users which
discover feature errors or biological function data associated with
features, to easily share such information with others.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Embodiments of the invention will now be described with
reference to the drawings in which:
[0018] FIG. 1 illustrates a substrate carrying multiple arrays,
such as may be fabricated by methods of the present invention;
[0019] FIG. 2 is an enlarged view of a portion of FIG. 1 showing
multiple ideal spots or features;
[0020] FIG. 3 is an enlarged illustration of a portion of the
substrate in FIG. 2;
[0021] FIG. 4 is a schematic diagram of an apparatus of the present
invention in the form of a central fabrication station;
[0022] FIG. 5 is a schematic diagram of an apparatus at a user site
which can execute a method of the present invention; and
[0023] FIG. 6 is a flowchart illustrating methods of the present
invention.
[0024] To facilitate understanding, identical reference numerals
have been used, where practical, to designate identical elements
that are common to the figures.
DETAILED DESCRIPTION OF THE INVENTION
[0025] In the present application, unless a contrary intention
appears, the following terms refer to the indicated
characteristics. A "biopolymer" is a polymer of one or more types
of repeating units. Biopolymers are typically found in biological
systems and particularly include polysaccharides (such as
carbohydrates), and peptides (which term is used to include
polypeptides and proteins) and polynucleotides as well as their
analogs such as those compounds composed of or containing amino
acid analogs or non-amino acid groups, or nucleotide analogs or
non-nucleotide groups. This includes polynucleotides in which the
conventional backbone has been replaced with a non-naturally
occurring or synthetic backbone, and nucleic acids (or synthetic or
naturally occurring analogs) in which one or more of the
conventional bases has been replaced with a group (natural or
synthetic) capable of participating in Watson-Crick type hydrogen
bonding interactions. Polynucleotides include single or multiple
stranded configurations, where one or more of the strands may or
may not be completely aligned with another. A "nucleotide" refers
to a sub-unit of a nucleic acid and has a phosphate group, a 5
carbon sugar and a nitrogen containing base, as well as functional
analogs (whether synthetic or naturally occurring) of such
sub-units which in the polymer form (as a polynucleotide) can
hybridize with naturally occurring polynucleotides in a sequence
specific manner analogous to that of two naturally occurring
polynucleotides. For example, a "biopolymer" includes DNA
(including cDNA), RNA, oligonucleotides, and PNA and other
polynucleotides as described in U.S. Pat. No. 5,948,902 and
references cited therein (all of which are incorporated herein by
reference), regardless of the source. An "oligonucleotide"
generally refers to a nucleotide multimer of about 10 to 100
nucleotides in length, while a "polynucleotide" includes a
nucleotide multimer having any number of nucleotides.
[0026] An "array", unless a contrary intention appears, includes
any one, two or three dimensional arrangement of addressable
regions bearing a particular chemical moiety or moieties (for
example, biopolymers such as polynucleotide sequences) associated
with that region. An array is "addressable" in that it has multiple
regions of different moieties (for example, different
polynucleotide sequences) such that a region (a "feature" or "spot"
of the array) at a particular predetermined location (an "address")
on the array will detect a particular target or class of targets
(although a feature may incidentally detect non-targets of that
feature). Array features are typically, but need not be, separated
by intervening spaces. In the case of an array, the "target" will
be referenced as a moiety in a mobile phase (typically fluid), to
be detected by probes ("target probes") which are bound to the
substrate at the various regions. However, either of the "target"
or "target probes" may be the one which is to be evaluated by the
other (thus, either one could be an unknown mixture of
polynucleotides to be evaluated by binding with the other). An
"array layout" refers collectively to one or more characteristics
of the features, such as feature positioning, one or more feature
dimensions, errors, or some indication of a moiety at a given
location. "Hybridizing" and "binding", with respect to
polynucleotides, are used interchangeably.
[0027] When one item is indicated as being "remote" from another,
this is referenced that the two items are at least in different
buildings, and may be at least one mile, ten miles, or at least one
hundred miles apart. "Communicating" information references
transmitting the data representing that information as electric or
electromagnetic (including light) signals over a suitable
communication channel (for example, a private or public network).
"Forwarding" an item refers to any means of getting that item from
one location to the next, such as by causing the item to be
physically transported (shipped) and includes, at least in the case
of data, physically transporting a medium carrying the data or
communicating the data. An array "package" may be the array plus
only a substrate on which the array is deposited, although the
package may include other features (such as a housing with a
chamber). A "chamber" references an enclosed volume (although a
chamber may be accessible through one or more ports). It will also
be appreciated that throughout the present application, that words
such as "top", "upper", and "lower" are used in a relative sense
only. "Fluid" is used herein to reference a liquid. A "set" or a
"sub-set" may have one or more members (for example, one or more
droplets). A "processor" includes any one or more electrical and/or
optical processors which can execute all the steps required of it,
or any hardware or software combination which will perform those or
equivalent steps, such as one or more general purpose digital
microprocessors suitably programmed from a computer readable medium
carrying necessary program code. Any "memory" includes any suitable
device or combination of devices in which a processor can store
and/or retrieve data as required, such as magnetic, optical, or
solid state storage devices (including magnetic or optical disks or
tape or RAM, or any other suitable device or combination of them,
either fixed or portable). Steps recited in a particular order in
relation to any method can be performed in that order or changed to
any order which is logically possible. Reference to a singular
item, includes the possibility that there are plural of the same
items present. All patents and other cited references are
incorporated into this application by reference.
[0028] Referring first to FIGS. 1-3, methods and apparatus of the
present invention may generate or use a contiguous planar substrate
10 carrying one or more arrays 12 disposed across a front surface
11a of substrate 10 and separated by inter-array areas 13. A back
surface 11b of substrate 10 does not carry any arrays 12. The
arrays on substrate 10 can be designed for testing against any type
of sample, whether a trial sample, reference sample, a combination
of them, or a known mixture of polynucleotides (in which latter
case the arrays may be composed of features carrying unknown
sequences to be evaluated). Each array 12 has associated with it a
unique identifier in the form of a bar code 356 described below. By
"unique" in this sense does not mean the identifier is absolutely
unique, but it is sufficiently long so as unlikely to be confused
with another identifier on another array (and is preferably unique
as to a particular central fabrication station on a given
communication channel). While ten arrays 12 are shown in FIG. 1 and
the different embodiments described below may use a substrate with
only one array 12 on it, it will be understood that substrate 10
and the embodiments to be used with it may have any number of
desired arrays 12. Similarly, substrate 10 may be of any shape, and
any apparatus used with it adapted accordingly. Depending upon
intended use, any or all of arrays 12 may be the same or different
from one another and each will contain multiple spots or features
16 of biopolymers such as polynucleotides. A typical array may
contain from more than ten, more than one hundred, more than one
thousand or ten thousand features, or even more than from one
hundred thousand features. All of the features 16 may be different,
or some or all could be the same. In the embodiment illustrated,
there are interfeature areas 17 between features, which do not
carry any polynucleotide. It will be appreciated though, that the
interfeature areas 17 could be of various sizes and configurations.
It will be appreciated that there need not be any space separating
arrays 12 from one another, nor features 16 within an array from
one another. However, in the case where arrays 12 are formed by the
deposition method as described above, such inter-array and
inter-feature areas 17 will typically be present. Each feature
carries a predetermined polynucleotide (which includes the
possibility of mixtures of polynucleotides). As per usual, A, C, G,
T represent the usual nucleotides. It will be understood that there
may be a linker molecule (not shown) of any known types between the
front surface 11a and the first nucleotide.
[0029] FIGS. 2 and 3 are enlarged views illustrating portions of
ideal features where the actual features formed are the same as the
desired features (sometimes referenced as the "target" or "aim"
features), with each feature 16 being uniform in shape, size and
composition, and the features being regularly spaced. In practice,
such an ideal result is difficult to obtain.
[0030] Referring now to FIG. 4, an apparatus of the present
invention which can execute a method of the present invention, will
now be described. The apparatus of FIG. 4 is a central fabrication
station which includes a substrate station 20 on which can be
mounted a substrate 10. Pins or similar means (not shown) can be
provided on substrate station 20 by which to approximately align
substrate 10 to a nominal position thereon. Substrate station 20
can include a vacuum chuck connected to a suitable vacuum source
(not shown) to retain a substrate 10 without exerting too much
pressure thereon, since substrate 14 is often made of glass.
[0031] A dispensing head 210 is retained by a head retainer 208.
The positioning system includes a carriage 62 connected to a first
transporter 60 controlled by processor 140 through line 66, and a
second transporter 100 controlled by processor 140 through line
106. Transporter 60 and carriage 62 are used execute one axis
positioning of station 20 (and hence mounted substrate 10) facing
the dispensing head 210, by moving it in the direction of arrow 63,
while transporter 100 is used to provide adjustment of the position
of head retainer 208 (and hence head 210) in a direction of axis
204. In this manner, head 210 can be scanned line by line, by
scanning along a line over substrate 10 in the direction of axis
204 using transporter 100, while line by line movement of substrate
10 in a direction of axis 63 is provided by transporter 60. In the
case where arrays 12 are to be fabricated by the deposition method,
transporter 60 can also move a load station (not shown) beneath
head 210 such that polynucleotides or other biopolymers obtained
from different vessels from a customer, can be loaded into head
210. Such a load station and method of use is described in detail
in U.S. patent application Ser. No. 09/183,604 for "Method And
Apparatus For Liquid Transfer" filed Oct. 30, 1998 by Tella et al,
incorporated herein by reference. In the case where arrays 12 are
to be fabricated by the in situ method, supplies of suitable
reagents can be provided in fluid communication with head 210, and
a flood station can be provided for steps in the process in which
all features to be formed are exposed to the same solution. Such
features are described in more detail in U.S. patent application
Ser. No. 09/356,249 for "Biopolymer Arrays And Their Fabrication"
filed by Perbost on Jul. 16, 1999, incorporated herein by
reference. Head 210 may also optionally be moved in a vertical
direction 202, by another suitable transporter (not shown). It will
be appreciated that other scanning configurations could be used. It
will also be appreciated that both transporters 60 and 100, or
either one of them, with suitable construction, could be used to
perform the foregoing scanning of head 210 with respect to
substrate 10. Thus, when the present application recites
"positioning" one element (such as head 210) in relation to another
element (such as one of the stations 20 or substrate 10) it will be
understood that any required moving can be accomplished by moving
either element or a combination of both of them. The head 210, the
positioning system, and processor 140 together act as the
deposition system of the apparatus. An encoder 30 communicates with
processor 140 to provide data on the exact location of substrate
station 20 (and hence substrate 10 if positioned correctly on
substrate station 20), while encoder 34 provides data on the exact
location of holder 208 (and hence head 210 if positioned correctly
on holder 208). Any suitable encoder, such as an optical encoder,
may be used which provides data on linear position.
[0032] Processor 140 also has access through a communication module
144 to a communication channel 180 to communicate with one or more
remote stations, such as locations at which arrays 12 are read.
Communication channel 180 may, for example, be a Wide Area Network
("WAN"), telephone network, satellite network, or any other
suitable communication channel. Communication module 144 may be any
module suitable for the type of communication channel used, such as
a computer network card, a computer fax card or machine, or a
telephone or satellite modem.
[0033] Head 210 may have multiple pulse jets, such as piezoelectric
or thermoelectric type pulse jets as may be commonly used in an ink
jet type of printer and may, for example, include multiple chambers
each communicating with a corresponding set of multiple drop
dispensing orifices and multiple ejectors which are positioned in
the chambers opposite respective orifices. Each ejector is in the
form of an electrical resistor operating as a heating element under
control of processor 140 (although piezoelectric elements could be
used instead). Each orifice with its associated ejector and portion
of the chamber, defines a corresponding pulse jet. It will be
appreciated that head 210 could, for example, have more or less
pulse jets as desired (for example, at least ten or at least one
hundred pulse jets). Application of a single electric pulse to an
ejector will cause a droplet to be dispensed from a corresponding
orifice. Certain elements of the head 210 can be adapted from parts
of a commercially available thermal inkjet print head device
available from Hewlett-Packard Co. as part no. HP51645A. A suitable
head construction is described in U.S. patent application Ser. No.
09/150,507 filed Sep. 9, 1998 by Caren et al. for "Method And
Multiple Reservoir Apparatus For Fabrication Of Biomolecular
Arrays", incorporated herein by reference. Alternatively, multiple
heads could be used instead of a single head 210, each being
similar in construction to head 210 and being movable in unison by
the same transporter or being provided with respective transporters
under control of processor 140 for independent movement.
[0034] As is well known in the ink jet print art, the amount of
fluid that is expelled in a single activation event of a pulse jet,
can be controlled by changing one or more of a number of
parameters, including the orifice diameter, the orifice length
(thickness of the orifice member at the orifice), the size of the
deposition chamber, and the size of the heating element, among
others. The amount of fluid that is expelled during a single
activation event is generally in the range about 0.1 to 1000 pL,
usually about 0.5 to 500 pL and more usually about 1.0 to 250 pL. A
typical velocity at which the fluid is expelled from the chamber is
more than about 1 m/s, usually more than about 10 m/s, and may be
as great as about 20 m/s or greater. As will be appreciated, if the
orifice is in motion with respect to the receiving surface at the
time an ejector is activated, the actual site of deposition of the
material will not be the location that is at the moment of
activation in a line-of-sight relation to the orifice, but will be
a location that is predictable for the given distances and
velocities.
[0035] The apparatus can deposit droplets to provide features which
may have widths (that is, diameter, for a round spot) in the range
from a minimum of about 10 .mu.m to a maximum of about 1.0 cm. In
embodiments where very small spot sizes or feature sizes are
desired, material can be deposited according to the invention in
small spots whose width is in the range about 1.0 .mu.m to 1.0 mm,
usually about 5.0 .mu.m to 500 .mu.m, and more usually about 10
.mu.m to 200 .mu.m.
[0036] The apparatus further includes a display 310, speaker 314,
and operator input device 312. Operator input device 312 may, for
example, be a keyboard, mouse, or the like. Processor 140 has
access to a memory 141, and controls print head 210 (specifically,
the activation of the ejectors therein), operation of the
positioning system, operation of each jet in print head 210, and
operation of display 310 and speaker 314. Memory 141 may be any
suitable device or devices in which processor 140 can store and
retrieve data, such as magnetic, optical, or solid state storage
devices (including magnetic or optical disks or tape or RAM, or any
other suitable device, either fixed or portable). Processor 140 may
include a general purpose digital microprocessor suitably
programmed from a computer readable medium carrying necessary
program code, to execute all of the steps required for by the
present invention for array production, or any hardware or software
combination which will perform those or equivalent steps. The
programming can be provided remotely to processor 140, or
previously saved in a computer program product such as memory 141
or some other portable or fixed computer readable storage medium
using any of those devices mentioned below in connection with
memory 141. For example, a magnetic or optical disk 324a may carry
the programming, and can be read by disk writer/reader 326.
[0037] A writing system which is under the control of processor
140, includes a writer in the form of a printer 150 which applies
identifiers onto substrate 10 by printing them in the form of the
bar codes 356 directly onto substrate 10 (or indirectly such as
onto a label later attached to the substrate), each in association
with a corresponding array 12 as illustrated in FIG. 1.
Alternatively, the identifiers can by applied onto a housing
carrying the substrate or label to be applied to such substrate or
housing. Printer 150 may accomplish this task before or after
formation of the array by the drop deposition system. The
identifiers may include a communication address which can identify
to a location (such as an end user station) an address of a remote
location on communication channel 180 from which will be
communicated first and/or update sets of feature characteristic
data for an array in response to a received communication of the
identifier for that array or, where the feature characteristic data
is biopolymer function data of the identifier or identity
information of one or more biopolymers on that array. As mentioned,
such feature characteristic data may include feature physical
characteristics or biological function data for one or more of the
biopolymers on array features. Such location will have a memory
accessible on the communication channel 180 carrying a database of
the data in association with corresponding array identifiers or
corresponding biopolymer identity information so as to facilitate
retrieval of the data upon receipt of the array identifier or
biopolymer identity information. The location identified by the
communication address may be that of communication module 144 or
alternatively that of another location. Examples of a communication
address may be a telephone number, computer ID on a WAN, or an
internet Universal Resource Locator. The writing system further
includes a data writer/reader 326 (such as an optical or magnetic
disk drive) which can write data to a portable computer readable
storage medium (such as an optical or magnetic disk). A cutter 152
is provided to cut substrate 10 into individual array units 15 each
carrying a corresponding array 12 and bar code 356.
[0038] FIG. 5 illustrates an apparatus at which an addressable
array 12 may be used, in particular a single "user station" which
is remote from the fabrication station (usually at the location of
the customer which ordered a received array 12). The user station
includes a processor 162, a memory 184, an array reader in the form
of a scanner 160 to read an array following exposure to a sample,
data writer/reader 186 (which may be capable of writing/reading to
the same type of media as writer/reader 320), and a communication
module 164 which also has access to communication channel 180.
Scanner 160 may include a holder 161 which receives and holds an
array unit 15, as well as a source of illumination (such as a
laser) and a light sensor 165 to read fluorescent light signals
from respective features on the array. Communication module 164 may
be any type of suitable communication module, such as those
described in connection with communication module 144. Memory 184
can be any type of memory such as those used for memory 141.
Scanner 160 can be any suitable apparatus for reading an array,
such as one which can read the location and intensity of
fluorescence at each feature of an array following exposure to a
fluorescently labeled sample. For example, such a scanner may be
similar to the GENEARRAY scanner available from Hewlett-Packard,
Palo Alto, Calif. Scanner 160 also includes though, a reader 163 to
read a the identifier in the form bar code 356 appearing on segment
15 as a read identifier signal. However, less preferably this
reader may be the same as the array reader. The scanning components
of scanner 160, holder 161, and reader 163 may all be contained
within the same housing of a single same apparatus.
[0039] It will be understood that there may be multiple such user
stations, each remote from the fabrication station and each other,
with the fabrication station of FIG. 4 acting as a central
fabrication station (that is, a fabrication station which services
more than one remote user station at the same or different times).
One or more such user stations may be in communication with the
fabrication station at any given time. It will also be appreciated
that processors 140 and 162 can be programmed from any computer
readable medium carrying a suitable computer program. For example,
such a medium can be any memory device such as those described in
connection with memory 141, and may be read locally (such as by
reader/writer 320 in the case of processor 140 or writer/reader 186
in the case of processor 162) or from a remote location through
communication channel 180.
[0040] The operation of the fabrication station will now be
described with reference to FIGS. 4 and 6. Reference numbers
appearing in FIG. 6 are shown in parentheses, with events at the
central fabrication station being within box 400 and those at a
single user station within box 500. Events for only one user
station remote from the central fabrication station are shown in
FIG. 6, but it will be understood that typically there will be many
such remote user stations. It will be assumed that a substrate 10
on which arrays 12 are to be fabricated, is in position on station
20 and that processor 140 is programmed with the necessary layout
information to fabricate target arrays 12. Processor 140 controls
fabrication of each array by depositing one or more drops of each
biopolymer onto a corresponding region (feature) on the substrate
in the case of the deposition method, or by depositing biomonomer
drops onto a region and sending the array to the flood station in
the case of the in situ method, so as to fabricate the array (400).
During or following array fabrication, arrays are inspected for
quality control ("QC")(420), for example for information on missing
features, misplaced features, features of incorrect dimensions, or
other physical characteristics, in a manner as described in U.S.
patent application Ser. No. 09/302,898 for "Polynucleotide Array
Fabrication" filed Apr. 30, 1999 by Caren et al., and application
Ser. No. 09/419,447 for "Biopolymer Array Inspection" filed Oct.
15, 1999 by Fisher, both incorporated herein by reference.
Available biological function data (434) for biopolymers on the
array is retrieved by processor 140 using biopolymer identity
information (such as sequence information) from portable storage
medium 324a and/or from one or more remote databases through
communication channel 180. "Biological function data" includes any
biological information on an array feature or a target, such as
information on the function of a target (such as cDNA) or its
complement (such as the mRNA from which the cDNA was derived), or
the gene from which either originated directly or indirectly (such
as the gene from which the mRNA complementary to a target cDNA, was
transcribed). For example, biological function data may include
information such as a gene identification (for example, a gene
name) or function from which is transcribed mRNA the DNA complement
of which is detected by a particular feature or features. Any other
information which might be of use to the end user may be forwarded
in addition to, or instead of, the biological function data. Any
such information includes information which is associated with an
array and may be used by the user in reading that array or
processing results read from the array (such as information on
where to obtain further information on the array layout or
processing of read results).
[0041] For each fabricated array 12, processor 140 will generate a
corresponding unique identifier and will save (430) this in memory
141 in association with the following (together forming a first set
of feature characteristic data 440): target array layout
information (including the location and identity of biopolymers at
each feature); quality control data (obtained in step 420); and
biological function data (434). Either before array fabrication on
substrate 10 has been commenced, or after it has been completed,
substrate 10 may be sent to writer 150 which, under control of
processor 140, writes (410) the identifier for each array 12 in the
form of bar codes 356 onto substrate 10 each in association with
its corresponding array (by being physically close to it in the
manner shown in FIG. 1). The substrate 10 is then sent to a cutter
152 wherein portions of substrate 10 carrying an individual array
12 and its associated local identifier 356 are separated from the
remainder of substrate 10, to provide multiple array units 15. The
array unit 15 is placed in package 340 along with storage medium
324b (if used) carrying the first set of feature characteristic
data and identifier for that same array unit 15 (and possibly for
other array units 15 which are to be sent to the same remote
customer location), and the package then shipped (480) to a remote
user station. The first set of feature characteristic data 440 for
each such array is forwarded (460) to the same remote users, either
by shipping to each user in association with the corresponding
array identifier on portable storage medium 324b, or by
communicating the first set over channel 180 in response to a
received communication from the remote station of the corresponding
array identifier. An identification of the features in the array to
which any data pertains, is included as a part of the feature
characteristic data. Note that the feature characteristic data may
only be for a sub-set of features on a given array. Alternatively,
in the less desired situation where the first set carries only
biological function data, biopolymer identifications may be used in
place of the array identifier.
[0042] At some time after fabrication of an array (for example,
after it has been shipped to a remote user), the fabrication
station may receive (450) further array quality control and/or
biopolymer biological function data from various sources. For
example, such may be received from a remote array user as
illustrated in FIG. 6 and described below. However, such may
additionally be received as a result of the fabricator's own
investigations or from remote databases. For example, quality data
(such as an error in the placement, dimensions, or presence) of one
or more features may be discovered by an individual at the
fabrication station by later inspection of some arrays of a same
feature pattern made in a same batch as other arrays previously
shipped to one or more customers. Additionally, biological function
data may be automatically retrieved by processor 140 at
predetermined time intervals from one or more remote databases over
communication channel 180 using data on the identity of the
biopolymers on previously fabricated arrays 12 which was saved in
memory 141. Any further such received quality or biological
function data is saved (470) in memory 141 in association with the
corresponding array identifier for later forwarding (472) to one or
more remote user stations (any one or more of which may be the same
or different from the remote user that provided all or part of such
further data).
[0043] The above sequence can be repeated at the fabrication
station as desired for multiple substrates 10 in turn. As mentioned
above, the fabrication station may act as a central fabrication
station for each of multiple remote user stations, in the same
manner as described above. Whether or not the fabrication station
acts as a central fabrication station, it can optionally maintain a
database of the first sets of feature characteristic data (and
update sets), each in association with the corresponding array
identifier. However, such database can be maintained at another
location and may be dispensed with in the case where the first sets
are shipped on portable storage media (such as medium 324b) to the
end users.
[0044] At the user station of FIG. 5, the resulting package 340 is
then received from the remote fabrication station. A sample, for
example a test sample, is exposed to the array 12 on the array unit
15 received in package 340. Following hybridization and washing in
a known manner, the array unit 15 is then inserted into holder 161
in scanner 160 for reading of the array (such as information
representing the fluorescence pattern on the array 12). The array
identifier is also machine read by the reader 163 in scanner 160
reading (501) the bar code 356 present on the array substrate 10 in
association with the corresponding array 12, while the array unit
15 is still positioned in retained in holder 161. Using read
identifier 356 (or biopolymer identification information),
processor 162 may then retrieve (502) the first set of feature
characteristic data for the array either from portable storage
medium 324b or from the database of such information in memory 141
by communicating the array identifier to that database through
communication module 164 and communication channel 180 and
receiving the corresponding first set of feature characteristic
data in response. In the latter situation, processor 162 may obtain
the communication address of communication module 144 by which to
access memory 141 (or the address of another database carrying the
identity map and associated identifier of array 12), from a
communication address in identifier 356 or by accessing a database
of manufacturer's communication addresses based on the read array
identifier (either from a local memory or by communication with a
remote database). Processor 162 may retrieve (504) the updated set
of feature characteristic data (470) in any of the same ways the
first set of feature characteristic data is obtained, although this
may be obtained at the same, earlier, or later time. The retrieved
first and updated sets may optionally be merged by replacing
feature characteristic data from the first set for a given feature
with corresponding data from the update set when the first set data
conflicts with the updated set data. For example, if the first set
indicates a particular feature is present and the updated set
indicates that it is not, the merged data indicates that feature is
not present. Thus, when use of the first and updated sets is
referenced in reading or processing read data from the array, this
may be done by way of using the merged data.
[0045] The array in array unit 15, while still positioned in holder
161, may be read to obtain read results. Processor 162 may cause
the array to be read, or the data obtained from reading to be
processed (which term includes interpretation of data), (510) using
the retrieved first and updated feature characteristic sets. For
example, if the sets together indicate a particular feature is
missing or severely defective then the scanner may simply avoid
reading such a feature at all. Alternatively, the read data from
such a feature may simply be deleted or ignored in any subsequent
processing, or processed results flagged as possibly being in error
due to that defective feature. As mentioned, the first and/or
updated sets may include biopolymer identification information, and
this can also be used to retrieve an additional updated set of
array feature characteristic data from one or more other local or
remote locations (by communication of the biopolymer
identifications and receiving in response, the updated set).
Results from the array reading can be processed results, such as
obtained by rejecting a reading for a feature which is below a
predetermined threshold and/or forming conclusions based on the
pattern read from the array (such as whether or not a particular
target sequence may have been present in the sample). The results
of the reading (processed or not) can be forwarded (such as by
communication) to be received at a remote location for further
evaluation and/or processing, or use, using communication channel
180 or reader/writer 186 and medium 190. This data may be
transmitted by others as required to reach the remote location, or
re-transmitted to elsewhere as desired.
[0046] During array reading or processing read data, a suspected
error in a feature characteristic (such as presence, placement,
dimensions, or biopolymer concentration) may be detected (520). The
suspected error can then be communicated (530) to the remote
fabrication station in association with the corresponding array
identifier or biopolymer identity data, where such information may
optionally be analyzed and, if considered appropriate (for example,
where the same suspected error for an array of a same feature
pattern is reported by multiple remote users) added to the updated
set of feature characteristic data. Alternatively or additionally,
further biological function data for a feature may be communicated
to the fabrication station for adding to the updated set. Such
further updated set is then available for retrieval by the same or
other remote users. In this manner, multiple remote users can
contribute to the continuous improvement in the updated feature
characteristic set.
[0047] In a variation of the above, it is possible that each array
12 and its substrate 10 may be contained with a suitable housing.
Such a housing may include a closed chamber accessible through one
or more ports normally closed by septa, which carries the substrate
10. In this case, the identifier for each array may be applied to
the housing.
[0048] Modifications in the particular embodiments described above
are, of course, possible. For example, where a pattern of arrays is
desired, any of a variety of geometries may be constructed other
than the organized rows and columns of arrays 12 of FIG. 1. For
example, arrays 12 can be arranged in a series of curvilinear rows
across the substrate surface (for example, a series of concentric
circles or semi-circles of spots), and the like. Similarly, the
pattern of regions 16 may be varied from the organized rows and
columns of spots in FIG. 2 to include, for example, a series of
curvilinear rows across the substrate surface (for example, a
series of concentric circles or semi-circles of spots), and the
like. Even irregular arrangements of the arrays or the regions
within them can be used provided the locations of features of
identified biopolymers are known. Further, the identifier shipped
to a remote user with the array need not be on the array substrate
or housing provided it is in some manner associated with the
corresponding array when shipped to the user. For example, the
identifier could be only on portable storage medium 324b or a paper
or other printed medium which is associated with the corresponding
array such as by being physically associated with it in the same
package 340.
[0049] The present methods and apparatus may be used to deposit
biopolymers or other moieties on surfaces of any of a variety of
different substrates, including both flexible and rigid substrates.
Thus, in any of the above described methods "biopolymer" or
"biopolymers" could more broadly be replaced with "moiety" or
"moieties". Preferred materials for the substrate provide physical
support for the deposited material and endure the conditions of the
deposition process and of any subsequent treatment or handling or
processing that may be encountered in the use of the particular
array. The array substrate may take any of a variety of
configurations ranging from simple to complex. Thus, the substrate
could have generally planar form, as for example a slide or plate
configuration, such as a rectangular or square or disc. In many
embodiments, the substrate will be shaped generally as a
rectangular solid, having a length in the range about 4 mm to 200
mm, usually about 4 mm to 150 mm, more usually about 4 mm to 125
mm; a width in the range about 4 mm to 200 mm, usually about 4 mm
to 120 mm and more usually about 4 mm to 80 mm; and a thickness in
the range about 0.01 mm to 5.0 mm, usually from about 0.1 mm to 2
mm and more usually from about 0.2 to 1 mm. However, larger
substrates can be used, particularly when such are cut after
fabrication into smaller size substrates carrying a smaller total
number of arrays 12. Substrates of other configurations and
equivalent areas can be chosen. The configuration of the array may
be selected according to manufacturing, handling, and use
considerations.
[0050] The substrates may be fabricated from any of a variety of
materials. In certain embodiments, such as for example where
production of binding pair arrays for use in research and related
applications is desired, the materials from which the substrate may
be fabricated should ideally exhibit a low level of non-specific
binding during hybridization events. In many situations, it will
also be preferable to employ a material that is transparent to
visible and/or UV light. For flexible substrates, materials of
interest include: nylon, both modified and unmodified,
nitrocellulose, polypropylene, and the like, where a nylon
membrane, as well as derivatives thereof, may be particularly
useful in this embodiment. For rigid substrates, specific materials
of interest include: glass; fused silica, silicon, plastics (for
example, polytetrafluoroethylene, polypropylene, polystyrene,
polycarbonate, and blends thereof, and the like); metals (for
example, gold, platinum, and the like).
[0051] The substrate surface onto which the polynucleotide
compositions or other moieties is deposited may be porous or
non-porous, smooth or substantially planar, or have irregularities,
such as depressions or elevations. The surface may be modified with
one or more different layers of compounds that serve to modify the
properties of the surface in a desirable manner. Such modification
layers, when present, will generally range in thickness from a
monomolecular thickness to about 1 mm, usually from a monomolecular
thickness to about 0.1 mm and more usually from a monomolecular
thickness to about 0.001 mm. Modification layers of interest
include: inorganic and organic layers such as metals, metal oxides,
polymers, small organic molecules and the like. Polymeric layers of
interest include layers of: peptides, proteins, polynucleic acids
or mimetics thereof (for example, peptide nucleic acids and the
like); polysaccharides, phospholipids, polyurethanes, polyesters,
polycarbonates, polyureas, polyamides, polyethyleneamines,
polyarylene sulfides, polysiloxanes, polyimides, polyacetates, and
the like, where the polymers may be hetero- or homopolymeric, and
may or may not have separate functional moieties attached thereto
(for example, conjugated),
[0052] Various further modifications to the particular embodiments
described above are, of course, possible. Accordingly, the present
invention is not limited to the particular embodiments described in
detail above.
* * * * *